<template>
  <div class="subject">
    <span>{{ num1 }}</span>
    <span>+</span>
    <span>{{ num2 }}</span>
    <span>=</span>
    <input type="number" v-model.trim.number="result" />
    <button @click="submit">提交</button>
  </div>
</template>

<script>
export default {
  name: "SubjectItem",
  data() {
    // 产生两个随机数
    const num1 = Math.floor(Math.random() * 101); // 0~100
    const num2 = Math.floor(Math.random() * 101); // 0~100
    return {
      num1,
      num2,
      result: "",
    };
  },
  methods: {
    submit() {
      if (this.result === "") return;
      // 回答正确、回答错误
      const textResult =
        this.num1 + this.num2 === this.result ? "回答正确" : "回答错误";
      this.$emit("submit", textResult);
    },
  },
};
</script>

<style scoped>
.subject {
  margin: 5px;
  padding: 5px;
  font-size: 20px;
}
.subject span {
  display: inline-block;
  text-align: center;
  width: 20px;
}
.subject input {
  width: 50px;
  height: 20px;
}
</style>